Polyblends comprising S-A copolymer and graft copolymer of S-A-acrylate onto a diene rubber

ABSTRACT

Clear, impact-resistant polymers having low permeability to gases and vapors are prepared by blending a resinous copolymer of acrylonitrile and styrene with a copolymer of acrylonitrile, styrene, and an acrylate ester prepared in the presence of a diene elastomer.

United States Patent [1 1 Giddings et al.

Warrensville Heights; Irving Rosen, Painesville, both of Ohio [73] Assignee: The Standard Oil Company,

Cleveland, Ohio [22] Filed: May 2, 1973 [21] Appl. No.: 356,581

Related US. Application Data [63] Continuation-in-part of Ser. No. 325,205, Jan. 19,

1973, abandoned.

[52] US. Cl. 260/876 R; 260/880 R [51] Int. Cl. C08L 51/04 [58] Field of Search 260/876 R, 880 R [56] References Cited UNITED STATES PATENTS 3,336,417 8/1967 Sakuma et a1. 260/880 Oct. 21, 1975 8/1970 Terenzi et a1 206/4531 3/1973 Lee et a1. 215/1 C FOREIGN PATENTS OR APPLICATIONS 965,851 8/1964 United Kingdom 260/876 R 731,736 4/1966 Canada 260/876 R Primary Examiner-Murray Tillman Assistant ExaminerC. J. Seccuro Attorney, Agent, or Firm.lohn F. Jones; Sherman J. Kemmer 5 7] ABSTRACT Clear. impact-resistant polymers having low permeability to gases and vapors are prepared by blending a resinous copolymer of acrylonitrile and styrene with a copolymer of acrylonitrile, styrene, and an acrylate ester prepared in the presence of a diene elastomer.

10 Claims, N0 Drawings 1 POLYBLENDS COMPRISING S-A COPOLYMER AND GRAFT COPOLYMER OF S-A-ACRYLATE ONTO A DIENE RUBBER This is a continuation-in-part application of our copending U.S. pat application Ser. No. 325.205 filed Jan. 19, 1973, now abandoned.

The present invention relates to novel polymeric compositions which when molded are clear, impactresistant, and have low permeability to gases and vapors, and more particularly pertains to clear, impactresistant polymeric compositions which function as gas and vapor barrier materials and are composed ofa conjugated diene monomer, acrylonitrile, styrene, and a lower alkyl acrylate ester, and to the process for preparing these compositions.

The novel polymeric products of the present invention are prepared by blending l a resinous copolymer of acrylonitrile, styrene, and optionally a lower alkyl ester of an olefinically unsaturated carboxylic acid with (2) a polymerization product of acrylonitrile, styrene. and a lower alkyl ester of an olefinically unsaturated carboxylic acid, and a rubber composed of the polymerization product of a major proportion of a conjugated diene monomer and a minor proportion of at least one member selected from the group consisting of an olefinically unsaturated nitrile and styrene.

The conjugated diene monomers useful in the pres ent invention include butadiene-1,3, isoprene, chloroprene, bromoprene, cyanoprene, 2,3-dimethylbutadienel ,3 Z-ethyl-butadiene-l ,3, 2,3-diethylbutadiene-1,3, and the like, and others. Most preferred for the purpose of this invention are butadiene and isoprene because of their ready availability and their excellent copolymerization properties.

The olefinically unsaturated nitriles useful in the present invention are the alpha,beta-olefinically unsaturated mononitriles having the structure wherein R is hydrogen, a lower alkyl group having from 1 to 4 carbon atoms, or a halogen. such compounds include acrylonitrile, alpha-chloroacrylonitrile, alphafluoroacrylonitrile, methacrylonitrile, ethacrylonitrile, and the like. The most preferred olefinically unsaturated nitriles in the present invention are acrylonitrile and methacrylonitrile, and mixtures thereof.

The lower alkyl esters of olefinically unsaturated carboxylic acids useful in the present invention are preferably thelower alkyl esters of alpha,beta-olefinically unsaturated carboxylic acids, and more preferred are the esters having the structure wherein R is hydrogen, an alkyl group having from I to 4 carbon atoms, or a halogen, and R is an alkyl group having from 1 to 6 carbon atoms. Compounds of this type include methyl acrylate, ethyl acrylate, the propyl acrylates, the butyl acrylates, the amyl acrylates, the hexyl acrylates; methyl methacrylate, ethyl methacrylate, the propyl methacrylates, the butyl methacrylates, the amyl methacrylates. and the hexyl methacrylates; methyl alphachloroacrylate, ethyl alphachloroacrylate, and the like. Most preferred in the present invention are methyl acrylate, ethyl acrylate, and methyl methacrylate.

The components of the polymeric compositions of the present invention can be prepared by any of the known general techniques of polymerization including bulk polymerization, solution polymerization, and emulsion or suspension polymerization techniques by batch, continuous or intermittent addition ofthe monomers and other components. The preferred method is polymerization'in an aqueous medium such as in an aqueous emulsion or suspension polymerization. The polymerization is preferably carried out in an aqueous medium in the presence of an emulsifier and a freeradical generating polymerization initiator at a temperature of from about 0' to 100C in the substantial absence of molecular oxygen.

The most preferred polymeric compositions embodied herein are those resulting from blending (A) a polymer resulting from the polymerization of I) from about to by weight of an alpha.beta-oletinically unsaturated mononitrile having the structure wherein R is a member selected from the group consisting of hydrogen, a lower alkyl group having from 1 to 4 carbon atoms and a halogen, and (2) from 10 to 30% by weight based on the combined weights of l) and (2) of sytrene with (B) a polymer resulting from the polymerization of 100 parts by weight of 1 50 to 90% by weight of an alpha,beta-olefinically unsaturated mononitrile having the structure wherein R has the foregoing designation, (2) from 1 to 35% by weight of styrene, and (3) from 2 to 29% by weight of an ester of an olefinically unsaturated carboxylic acid having the structure wherein R and R have the foregoing designations in the presence of from 20 to 600 parts by weight of (4) a rubbery copolymer of a conjugated diene monomer selected from the group consisting of butadiene and isoprene and at least one member selected from the group consisting of an olefinically unsaturated mononitrile having the structure wherein R has the foregoing designation and styrene, said rubbery copolymer containing from 50 to by weight of polymerized conjugated diene monomer and from 50 to 5% by weight of polymerized olefinically unsaturated nitrile or styrene or both. The preferred polymeric compositions of this invention contain from 60 to 907! by weight of (A) and correspondingly from 40 to 10% by weight of (B).

ymer. A part of this latex was coagulated and the resin was isolated and dried. The dried polymer was found to have the following physical properties:

The blended polymeric compositions embodied in 5 ASTM hcat distortion temperature 92C this mvennon be prepared by bleridhng the i notched lzod impact strength 0.13 foot pounds (B) components in latex form or by intimately mixing per inch or otc the dry (A) and (B) components on a rubber mill. in flvxurfll Smngth "P l h k I flexural modulus 5.60 X ps1 an mterna mixer, or 0t er nown p0 ymer mixing ensue Strength 918 X :1 psi means. The blends can also be prepared by mixing the 10 clarity excellent (A) and (B) components in solution or by adding either plam'cmdcr torque meter gums or f other whflch B. A rubber latex was prepared by polymerizing, with so r t ere n t 8 most pre t continuous agitation at 45C in the substantial absence proce t e P ymer blends are made by combmmg of oxygen, a mixture of the following ingredients: the aqueous latices of components (A) and (B).

The novel polymeric products of the present invenlngrcdignl Parts tion are thermoplastic materials which can be thermol I 35 formed into a wide variety of useful articles in any of c 65 the conventional ways employed with known thermofatty-acid soap 1:4 1

. azobisisobutyronitrile 0.3 plastic polymeric materials such as by extrusion, mill Hmdccy, mcrcupmn 0.5 mg, molding, drawing, blowing; etc. The polymeric water 200 products of this invention have excellent solvent resistame and 'mpact strength and low Permeab'hty The polymerization was carried out for about 22 hours 8 and Vapors make them r useful m P 25 to a conversion of 92% and a total solids of 33%. aging industry, and they are particularly useful in the A graft polymer was prepared by the p0|ymeri manufacture of bottles, f lm, and other types of conzation of the following ingredients: talners for liquids and solids.

This invention is further illustrated in the following rngrcdicm Parts examples in which the amounts of the various materials 300 mentioned are expressed in parts by weight unless othlatex m erwise specified. (B of this example) Alipal (30-436 3 EXAMPLE 1 acrylonitrilc styrene 5 A. A resin was prepared from the following recipe: m y flcrxlulc 20 35 limoncnc dimercaptan 2 potassium pcrsulfatc 0.15

Ingredient Parts The water and emulsifier (Alipal CO-436) were mixed acrylonltrilc 75 styrene 25 and the pH of the mixture was ad usted to 7 with dilute wa r 4O alkali. The rubber latex was added to this mixture and Alipal CO-436* 1. Modem mcrcapmn L7 the pl-l was aga n ad usted to 7 using dilute hydrochlorlc acid. This mixture was then added to the polymeri- Ammoniuni salt of sulfatud nimyl phcnoxy poly(cthylcnuoxy) ethanol. ation reactor had already been charged the other ingredients. Mixing was commenced and the re- The Water and emulslfler p were mixed 5 actor was purged with nitrogen for 10 minutes. The reand the resulting solution, which had a pH of about 6.6, actor contents were then brought to 65C and mainwas transferred to the polymerization reactor. Potastained at this temperature during the polymerization m p lf P r w h n d d with s irtime of 5 hours. The polymerization was carried to ring and the reactor was purged with nitrogen for 10 about conversion, minutes. The mixture was then brought to and main- 50 Latices of A d C above were bl d d to f tained at 70C and the feed, which was composed of acbl d h i rubber contents of 12, 14, and 16% by ryl m rll tyrene, and t-dodecyl mercaptan. was weight based on the total weight of the resin. The readded to the stirred reactor mixture at a controlled rate sulting blends were coagulated in boiling water conso that a time of 5% hours was required for completion taining aluminum sulfate toyield 95 to Of final of the addition of the feed material. The final latex was 55 resin d t Th physical properties of these blends obtained in about 95% conversion of monomers to polare given in Table 1.

Table 1 Blend, Notched Izod Brabender Solids Flexural Flexural Tensile lmpact Strength Plasticorder Basis ASTM Strength Modulus Strength (ft lbs/inch Torque Rubber A/C HDT* (X 10 psi) (X 10 psi) (X 10 psi) of notch) (meter grams) in Blend 47/25 91C 11.1 4.87 7.19 1.02 1750 12% 52.4/20 90C 14.8 4.80 10.20 1.10 1950 12% 34.4/20 88C 6.6 4.31 8.46 0.97 1550 16% 47.5/25 86C 14.7 4.30 11.10 1.56 1580 12% 52.25/25 87C 13.7 3.81 10.60 1 45 2000 14% 'ASTM Heat Distortion Temperature EXAMPLE 2 A. An acrylonitrile-styrene resin in latex form was prepared from the following ingredients:

"A pulyoxyethylene glyccride ester.

A mixture of RO(CH,CH O-), PO ,M and lRO-(CH CH,O-),,l PO,M wherein n is a number from 1 to 40. R is an alkyl or alkaryl group and preferably a nonyl phenyl group. and M is hydrogen. ammonia or an alkali metal. This material is sold by GAF Corporation.

The emulsifiers, Gafac RE-61O and G-1300, were disous KOH. The elastomer B latex was then added and the mixture was stirred and purged with nitrogen for minutes. The mixture was then heated to 65C and the persulfate catalyst was added with continued stirring. The mixture of acrylonitrile, styrene, methyl acrylate, and limonene dimercaptan was added continuously over a 4-hour period at 65C. After completion of the addition of the monomers the reaction was allowed to continue with stirring at 65C for an additional hour.

D. Latices of A and C of this example were mixed so as to achieve a final rubber level of 12% in the resin. The blended latices were coagulated in an aqueous alum solution at 90 to 95C. The resin was dried and was found to have the following properties:

ASTM heat distortion temperature 97C (66 psi) solved in the water and the pH of the resulting solution was adjusted to 6-7 with dilute aqueous KOH. This solution was stirred and purged with nitrogen for about 20 minutes. The solution was then heated to 70C and the mixture of acrylonitrile, styrene, and limonene dimercaptan was then added continuously and in a separate stream was added continuously the ammonium persulfate-water solution. Addition of the monomers and catalyst required about 5 hours. A latex resulted which represented about 95% conversion of monomers to polymer.

B. An elastomer of butadiene-acrylonitrile and styrene was prepared as follows using the following ingre- N-hydroxyethyl ethylene diamine triacetic acid.

The polymerization was carried out with agitation at 60C for about 16 hours to give a conversion of about 87% of monomers to polymer. The product was in the The Gafac RE-6l0 was dissolved in the water and the pH of the solution was adjusted to 6-7 with dilute aque- 6 clients:

lngrcdient Parts water 175 Gafac RS-71()* 1.0 Hampol 1(;,l2()"' 0.1 styrene 20 acrylonitrilc 5 butadiene 75 azobisisohutyronitrile 0.25 t-dodecyl mcreaptan 0.5

*Tridecyl polyethylene-my phosphate.

notched lzod impact strength flexural strength flexural modulus tensile strength ASTM D-1003 haze ASTM D-l003 transmission ycllowness index (ASTM D-1925) 87C (264 psi) 1.04 foot pounds per inch of notch 15 X 10- psi 4.5 x 10 psi 10.2 x 10* psi 21.2

E. The procedure of C of this example was repeated except that parts of styrene and no methyl acrylate were used in the graft polymerization.

notched Izod impact strength 0.75 foot pounds per inch of notch ASTM D-l003 haze 42.8 ASTM D-1003 transmission 73.7'71 yellowness index (ASTM D-l925) 52.2

Thus, it can be seen by direct comparison that this resin, which is outside the scope of the present invention, is inferior to the resins of this invention as exemplified in D of this example.

EXAMPLE 3 A. The procedure of Example 1-A was repeated to produce a latex of an acrylonitrile/styrene copolymer.

B. The procedure of Example 1J-B.was repeated except that 25 parts of styrene and parts of butadiene were used in the polymerization.

C. The procedure of Example l-C was repeated using latex B above instead of latex B of Example 1.

D. Latices A and C above were blended to form blends having rubber contents of 10 and 14% by weight based on the total weight of the final resin. The resulting blends were coagulated in boiling water containing aluminum sulfate to yield 95, to of final resin product. The physical properties of these blends are given in Table 2.

Table 2 Notched Izod Flexural Flexural Tensile lmpact Strength Rubber ASTM Strength Modulus Strength (ft lbs/inch) Yellowness in HDT (X 10'' psi) (X 10 psi) (X 10 psi) of notch) Transmission Haze lndex Blend B. The procedure of Example 2-B was repeated. C. The procedure of Example 2-C was repeated.

We claim:

1. The polymeric composition resulting from blending Latlces A and C of this example were mixed so A. a polymer resulting from the polymerization of a as to achieve final rubber levels of and 14% in the monomer component consisting f resin. The blended latices were coagulated in an aqueous alum solution at 90 to 95C. The final resin was from about 70 m y weight alpha, dried and was f d to have the physical properties 1.0 beta-olefinically unsaturated mononitrile having shown in Table 3. the Structure Table 3 Notched Izod Flexural Flexural Tensile Impact Strength Rubber ASTM Strength Modulus Strength (ft lbs/inch) Yellowness in HDT (X 10 psi) (X 10 psi) (X 10 psi) of notch) Transmission Haze Index Blend EXAMPLE 5 CH jCN A. The procedure of Example l-A was repeated.

8. The procedure of Example 1B was repeated using.

the following recipe:

Ingredient Parts water hutadiene styrene t-dodecyl mereaptan P & G soap flakes Duxad I 1* potassium persulfate Naphthalene sulfonie acid-formaldehyde condensate-sodium salt.

C. A graft polymer was prepared by the polymerization of the following ingredients:

(2 mercapto propionate) modifier) ammonium persulfate (1.1

The pH was adjusted to about 5 with citric acid. The reaction was carried out at 65C in the substantial absence of molecular oxygen. The monomer-modifier mixture was fed continuously to the reactor mixture over a 2-hour period. A conversion of 90% was achieved.

D. A blend of A/C was prepared in the solids weight ratio of 682/100. The coagulated polyblend was found to have a Brabender plasticorder torque of 1690 meter grams, a heat distortion temperature of 86C, a notched Izod impact strength of 1.1 foot pounds per inch of notch, and excellent clarity and little or no color. The final resin was found to contain about 11% by weight of the butadiene-styrene rubber.

wherein R is a member selected from the group consisting of hydrogen, a lower alkyl group having from 1 to 4 carbon atoms and a halogen, and

2. from 10 to 30% by weight based on the combined weights of 1) and (2) of styrene with B. a polymer resulting from the polymerization of 100 parts by weight of 1. from 50 to by weight of an alpha, betaolefinically unsaturated mononitrile having the structure wherein R has the foregoing designation,

2. from 1 to 35% by weight of styrene, and

3. from 2 to 29% by weight of an ester of an olefinically unsaturated carboxylic acid having the structure CH =COOR wherein R, is hydrogen, an alkyl group having from 1 to 4 carbon atoms, and a halogen, and R is an alkyl group having from 1 to 6 carbon atoms in the presence of from 20 to 600 parts by weight of 4. a rubbery copolymer of a conjugated diene monomer selected from the group consisting of butadiene and isoprene and at least one member selected from the group consisting of an olefinically unsaturated mononitrile having the structure wherein R has the foregoing designation and styrene. said rubbery copolymer containing from 50 to 95% by weight of polymerized conjugated diene monomer and from 50 to by weight of the other monomer component. 2. The composition of claim 1 wherein (A) (l) is acrylonitrile.

3. The composition of claim 2 wherein (B) (l) is acrylonitrile.

4. The composition of claim 3 methyl acrylate.

5. The composition of claim 4 wherein (B) (4) is a rubbery copolymer of butadiene.

6. The process comprising blending A. a polymer resulting from the polymerization in an aqueous medium of a monomer component consisting of 1. from about 70 to 90%: by weight of an alpha,-

beta-olefinically unsaturated mononitrile having the structure wherein (B) (3) is wherein R is a member selected from the group consisting of hydrogen, a lower alkyl group having from 1 to 4 carbon atoms and a halogen, and

2. from to 30% by weight based on the combined weights of 1) and (2) of styrene with B. a polymer resulting from the polymerization in an aqueous medium of 100 parts by weight of 1. from 50 to 90% by weight of an alpha,betaolefinically unsaturated mononitrile having the structure wherein R has the 10 foregoing designation, 2. from 1 to 35% by weight of styrene. and 3. from 2 to 29% by weight of an ester of an olefinically unsaturated carboxylic acid having the structure wherein R is hydrogen, an alkyl group having from I to 4 carbon atoms, and a halogen, and R is an alkyl group having from 1 to 6 carbon atoms in the presence of from 20 to 600 parts by weight of 4. a rubbery copolymer ofa conjugated diene monomer selected from the group consisting of butadiene and isoprene and at least one member selected from the group consisting of an olefinically unsaturated mononitrile having the structure bery copolymer of butadiene (B)( l is acryloni- (B)(3) is methyl 

1. THE POYMERIC COMPOSITION RESULTING FROM BLENDING A. A POLYMER RESULTING FROM THE POLYMERIZATION OF A MONOMER COMPONENT CONSISTING OF
 1. FROM ABOUT 70 TO 90% BY WEIGHT OF AN ALPHA, BETAOLEFINICALLY UNSATURATED MONONITRILE HAVING THE STRUCTURE
 1. FROM 50 TO 90% BY WEIGHT OF A ALPHA, BETA-OLEFINICALLY UNSATURATED MONONITRILE HAVING THE STRUCTURE
 2. FROM 10 TO 30% BY WEIGHT BASED ON THE COMBINED WEIGHTS OF (1) AND (2) OF STYRENE WITH B. A POLYMER RESULTING FROM THE POLYMERIZATION OF 100 PARTS BY WEIGHT OF
 2. FROM 1 TO 35% BY WEIGHT OF STYRENE, AND
 2. The composition of claim 1 wherein (A) (1) is acrylonitrile.
 2. from 10 to 30% by weight based on the combined weights of (1) and (2) of styrene with B. a polymer resulting from the polymerization in an aqueous medium of 100 parts by weight of
 2. from 10 to 30% by weight based on the combined weights of (1) and (2) of styrene with B. a polymer resulting from the polymerization of 100 parts by weight of
 2. from 1 to 35% by weight of styrene, and
 2. from 1 to 35% by weight of styrene, and
 3. from 2 to 29% by weight of an ester of an olefinically unsaturated carboxylic acid having the structure
 3. from 2 to 29% by weight of an ester of an olefinically unsaturated carboxylic acid having the structure
 3. The composition of claim 2 wherein (B) (1) is acrylonitrile.
 3. FROM 2 TO 29% BY WEIGHT OF AN ESTER OF AN OLEFINICALLY UNSATURATED CARBOXYLIC ACID HVING THE STRUCTURE
 4. A RUBBERY COPOLYMER OF A CONJUGATED DIENE MONOMER SELECTED FROM THE GROUP CONSISTING OF BUTADIENE AND ISOPRENE AND AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF AN OLEFINICALLY UNSATURATED MONONITRILE HAVING THE STRUCTURE
 4. a rubbery copolymer of a conjugated diene monomer selected from the group consisting of butadiene and isoprene and at least one member selected from the group consisting of an olefinically unsaturated mononitrile having the structure
 4. The composition of claim 3 wherein (B) (3) is methyl acrylate.
 4. a rubbery copolymer of a conjugated diene monomer selected from the group consisting of butadiene and isoprene and at least one member selected from the group consisting of an olefinically unsaturated mononitrile having the structure
 5. The composition of claim 4 wherein (B) (4) is a rubbery copolymer of butadiene.
 6. The process comprising blending A. a polymer resulting from the polymerization in an aqueous medium of a monomer component consisting of
 7. The process of claim 6 wherein (A)(1) is acrylonitrile.
 8. The process of claim 7 wherein (B)(1) is acrylonitrile.
 9. The process of claim 8 wherein (B)(3) is methyl acrylate.
 10. The process of claim 9 wherein (B)(4) is a rubbery copolymer of butadiene. 